Rectilinear edge flanging tool for sheet metal workpieces



Oct. '27, 1970 c. 1', F I L 3,535,905

RECTI-LINEAR EDGE FLANGING TOOL FOR SHEET METAL WORKPIECES Filed Jan. 23, 1968 s Sheets-Sheet 1 4 I I l I l Il"" |1 l l 72 l 1/72 I 7| l 1' .l -70 "W g l6 2o m 1 u g 54 6o 50 55 4 ma. '2

CHARLES T. PRIZE L FIG. 1

Q Oct. 27; 1970 c, 1', mz L 3,535,905

RECTILINEAR EDGE FLANGING TOOL FOR SHEET METAL WORKPIECES Filed Jan. 23, 1968 3 Sheets-Sheet 2 CHAQLEG T. F [2/2 E L L Filed Jan. 25, 1968 Oct. 27, 1970 c. r. FRIZELLV 3,535,905

RECTILINEAR EDGE FLANGING TOOL FOR SHEET METAL WORKPIECES 3 Sheets-Sheet 3 United States Patent 3,535,905 RECTILINEAR EDGE FLANGING TOOL FOR SHEET METAL WORKPIECES Charles T. Frizell, St. Louis County, Mo., assignor to Engel Industries, Inc., a corporation of Missouri Filed Jan. 23, 1968, Ser. No. 699,819 Int. Cl. B21d 19/06 US. Cl. 72--220 7 Claims ABSTRACT OF THE DISCLOSURE A flanging tool for turning 180 edge flanges, especially suited for the ends of sheet metal ducts, includes a table surface with a blade-like projecting forming edge, an outboard clamp mechanism, and a longitudinal track. A traversing carriage, mounting a plurality of forming rolls which work against the projecting table edge, turns a flange downwardly, around and upwardly beneath the edge. Adjacent to the downward-forming rolls, are rolls beneath the projecting edge which support the edge on the forming stroke. On the return stroke, these rolls press out the flange more tightly against the under surface of the edge.

This invention relates to rectilinear edge flanging tools for sheet metal workpieces, and particularly to the tools for turning 180 flanges on the ends of sheet metal duct sections.

The problem, exemplified in the construction of sheet metal ducts for air conditioning systems and the like, is that such 180 flanges must usually be formed on two opposite edges of a seamed rectilinear duct. Adjacent duct sections with such 180 flanges, are joined by flattened C-shaped drive cleats. Unless the 180 flanges are smooth and precise, such drive cleats cannot be readily attached.

A machine adapted to form such flanges by folding is shown in US. patent to Engel and Mace No. 2,973,796. The machine there disclosed forms the 180 bend by a folding operation; if large widths of duct are to be accommodated, the major machine elements must be made broad enough to accommodate them; and a machine of modest size has limited utility. It is common to form such 180 bends with hand tools; this can be accomplished successfully only by someone with substantial skill and experience.

SUMMARY OF THE INVENTION One of the purposes of the present invention is, while holding a workpiece in fixed position, to turn a flange by a traversing roll mechanism, this may be the same regardless of the width of the workpiece to be flanged; only the length of its travel need be changed. Other purposes are to so roll an edge flange as to achieve a tight 180 bend without appreciable spring-back, and to press the flange so formed flat and even. A further purpose is to utilize both traversing and return movements of the roll carriage to accomplish the forming operation.

Generally summarizing (and without limitation), the present invention includes a workpiece support structure having a rectilinear forming edge which projects therefrom in a plane; workpiece securing means such as a clamp mechanism including adjustably-spaced clamp pads actuated from outward of the forming edge and projecting thereover (e.g., into the end of a duct to be flanged); a track parallel to and below the level of the forming edge; a carriage mounted thereon; means to draw the carriage along the track in a forming movement and to return it in a return movement; forming rolls carried by the carriage to bend the edge of a workpiece into a flange Patented Oct. 27, 1970 downward, around and beneath the projecting forming edge; and means, such as rolls on the horizontal axis, mounted on the carriage beneath the level of the projecting edge, to support the projecting edge against the pressure of the downward-forming rolls and, on the return movement of the carriage, to press and flatten the formed flange against the under surface of the edge.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of an edge flanging tool of the embodying invention, with the carriage in position for a forming stroke. The phantom lines show the carriage position prior to its return stroke; also a sheet metal duct in position for flanging.

FIG. 2 is a plan view thereof.

FIG. 3 is a view thereof from the left end of FIG. 1, the clamp mechanism being in raised position, its lowered and locked position being shown in phantom lines.

FIG. 4 is an enlarged elevational view of the carriage as seen along line 44 of FIG. 2.

FIG. 5 is a plan view of the carriage.

FIG. 6 is a right end view thereof.

FIG. 7 is a schematic view showing the initial downward forming operation achieved by the first forming roll, at the right end of FIG. 4-.

FIG. 8 is a view of the final forming operation achieved by the forming roll at the left end of FIG. 4.

FIG. 9 is a fragmentary view illustrating the upward pressing operation on the return stroke of the carriage.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1, 2 and 3, a workpiece support structure generally designated a, preferably formed by welding, includes four upright legs b and horizontal top surface supports 0, onto which are secured a steel table surface d with a gage bar e along its left edge. Lower horizontal braces 1 support an electric motor g and gear reducer h, hereinafter referred to.

Secured, as by bolting, along the forward side of the table surface at, immediately below its level, is a rigid rectangular support bar 11, as shown in FIGS. 7 and 8. To its upper surface is secured, by counter-sunk screws 12, a blade-like projecting forming edge 15 which eX- tends the full length of the table surface d and whose upper surface is co-planar with it. The outer edge 16 of the forming edge 15 serves as the edge about which the 180 flange is to be formed, as hereinafter described; a projecting portion 17 of its under surface outwardly of the support bar 11 is utilized in the manner hereinafter described.

The forming edge 15 is preferably formed of steel having spring-like resilience, which permits it to withstand the forces of the forming operation and to deflect slightly, as required in the operation hereinafter to be described, especially where variation in thickness of sheet metal workpieces must be accommodated.

At a level below the forming edge 15, and mounted at its ends on welded girders 19 which extend diagonally forward from midpoints of the side horizontal table supports 0, is an elongated vertical plate which constitutes the carriage track, generally designated 20. As will be seen from FIGS. 1 and 2 it extends parallel to the edge 15 and is sufficiently longer than the table surface 0 to accommodate a carriage, generally designated 30, on

. either side thereof, and still farther outwardly, to be relower braces f a pair of pillow blocks which support a drive shaft 26, chain-driven reversibly by the gear reducer h and having an outer driving sprocket 27 which engages the carriage drive chain 24-. An adjustable tension sprocket 28 supported adjacent to one of the legs 11 completes the driving assembly, as shown in FIGS. 1 and 3.

The carriage track 20 has horizontal upper and lower edges 29 on which the carriage generally designated 30 is mounted. As best seen in FIGS. 4, 5 and 6 the carriage 30 consists of a vertical plate 31 having upper and lower edge cut-outs 31 and 31". The plate 31 has at its outer side a narrow horizontal forming roll support shelf 32, stabilized by three triangular ribs 33. Bolted to project to the inner side of the plate 31 are upper grooved rollers 34 and lower grooved rollers 35. On welded lugs 36, which project horizontally inward adjacent to the upper rollers 34, are vertical bolts 37 bearing two inner guide rollers 38; these are positioned inwardly of the track 20. Somewhat similarly, in the lower cut-out 31" is welded a horizontal lug 36' bearing a vertical bolt 37' on which is mounted an outer guide roller 38'.

A pair of lugs 39 welded to the support shelf 32 outwardly of each of the end ribs 33 serves to attach the chain 24 to the carriage 30, whereby the driving assembly heretofore described serves as means to draw the carriage along the track 20. The motor g being of the reversible type, operated by conventional controls (not shown), the carriage 30 may be traversed initially for a forming stroke from the solid line position shown in FIG. 1 to the phantom line position, and thence returned on a return stroke.

Mounted along the support shelf 32 of the carriage 30 are a series of progressive forming rolls generally designated 40, each being free to rotate on a vertical bolt 41. In the embodiment illustrated, five such progressive forming rolls 42, 43, 44, 45, 46 are utilized. As shown in the schematic views FIGS. 7 and 8, these are located in workpiece forming adjacency to the rectilinear forming edge 15. When the carriage 30 is drawn along the track 20, the vertical bolts 41 describe planes which are substantially perpendicular to the support plane of the table surface a.

The configurations of the progressive forming rolls 42- 46 are adapted, in relation to the projecting edge 15, to form a flange progressively downward and around and thence upwardly under the blade edge 15. Specifically, the first progressive forming roll 42, illustrated at the right side, includes a forming surface of revolution 42 inclined downwardly from the forming edge 15 and outwardly toward its mounting bolt 41. This forming surface of revolution 42' extends partly above and partly below the support plane defined by the table surface a. The next forming roll 43 includes a forming surface of revolution 43' inclined downward at a greater angle; the third roll 44 includes a vertical forming surface of revolution 44. These forming surfaces of revolution 42', 43', 44' are, at the level of the forming edge 15, spaced forward of its outer edge 16 sufliciently to accommodate a thickness of the workpiece to be formed. The fourth of the progressive forming rolls 45 has a similarly located surface portion 45' adapted to control the point at which the flange is formed downwardly, and also includes a larger forming surface of revolution 45" therebeneath which is directed inwardly beneath the under surface 17 of the forming edge 15. This inwardly directed surface 45" therefore commences the forming of the flange upwardly against the under surface 17. Such upward forming is brought to 180 at the forming roll 46 by its upwardly presented surface of revolution 46", while its vertically presented surface of revolution 46 continues to control the point of flanging, as best seen in FIG. 8.

At the forward end of the carriage (the right side as viewed in FIG. 4) the plate 31 has an upward projecting portion 48 in which are mounted, on horizontal axes forward and aft of the first forming roll 42, bolts 49 which serve as axes for a pair of edge support rolls 50; these extend aft immediately beneath the under surface 17 of the forming edge 15, as best shown in FIG. 7. As the carriage 30 is drawn along the track 20, the bolts 49 define a plane parallel to the edge under surface 17 spaced sufficiently beneath it to provide for its passing support by the upper surface of the rolls 50. Alternately, other forming edge support means, such as a block of material having a lubricated surface, might be used to overcome the downward deflection of the forming edge 15 under the downward bending force applied by the roll 42 in the manner shown in FIG. 7 and similarly by the next forming roll 43. The spacing of the edge support rolls 50 adjacent to the downward forming rolls 42, 43 but forward of the inward forming rolls 45, 46 avoids interference with the edge of the workpiece as it is subsequently flanged inward.

A clamp mechanism is provided to secure a workpiece, such as the open end of a sheet metal duct 1', to the table surface d. At the forward or working side of the apparatus, immediately above the left and right legs I) are welded upward extension plates 53, at whose upper ends are forward extending plates 54, bored to provide aligned pivot mounts for a clamp bar 55, outwardly of the forming edge 15 and parallel thereto and above the level of the track 20 and carriage means 30. As best seen in FIG. 7, the clamping bar has a keyway 56. Along its length between its pivot mounts in the plates 54 are a plurality of spaced-apart clamp pads generally designated 60. Each includes a sleeve portion 61 fitted slidably on the bar 55 and having a tapped bore 62 accommodating a wing bolt 63 by which it is secured to the bar 55. Each clamp pad also has a rigid arm portion 64 which extends over and inwardly of the edge 15 and has a tapped bore 65 which in the clamping position is vertical, as shown in FIG. 7. The bore 65 receives the threaded stem 66 which extends upward from a clamping foot 67, whose fiat bottom surface 68 is presented against a workpiece; the bottom surface 68 extends over that part of the edge 15 which is supported by the bar 11 and preferably part over the table surface d.

At each end of the bar 55 outward of a spacer 69 is an operating lever 70 which for clamping is locked in horizontal position of the lever 70. Illustrated for this purpose is the hooked end 71 of a locking arm 72 pivot mounted to the support 0 by a bolt 73. Other more s0phisticated clamp-locking methods may be used.

The plurality of pads 60 and their ability to be separated from each other and adjustably positioned along the bar 55, permits accommodation between them of vertical edges of the open end of a sheet metal duct of any convenient width, such as the duct j shown in FIGS. 1 and 2 in phantom lines. In use, clamp pads 60 are positioned to fit within the open end of a duct 1 placed on the table surface d against the gage e. Such a duct j is shown fragmentarily in FIG. 8; in FIG. 7 its lower surface k is shown as well as its projecting longitudinal edge In to be flanged. The operating levers 70 of the clamp mechanism are then moved downward to horizontal position, as shown in FIG. 3, and the hooked ends 71 of the locking arms 72 are engaged thereover, thus setting the clamping feet 67 firmly on the duct lower surface k just inwardly of the longitudinal edge In and of the greater part of the projection of the forming edge 15 beyond the bar 11.

The motor g is then engaged to cause the chain 24 to draw the carriage 30 in the forming stroke, from left to right in FIG. 1. As it traverses the workpiece edge m, the progressive forming rolls 42-46 perform their flanging operations which have been described, starting with the downward bend shown in FIG. 7 and ending with the upward forming of the flange as shown in FIG. 8. During this forming step, the support rolls 50 resist downward deflection of the edge 15 from the forming forces applied by the first two rolls 42, 43 and due to downward inclination of their forming surfaces 42', 43.

When the carriage has traveled past the duct j, it is stopped and the direction of travel is reversed. This may be done automatically by familiar microswitch mechanism when the phantom line position at the right side of the FIG. 1 is reached. On the return stroke, shown in FIG. 9, the supporting rolls S perform an entirely different function. Inasmuch as projecting edge is springy, and may deflect upwards to accommodate material of various gages, the 180 flange to which the longitudinal edge m has been formed may be accommodated under the surface 17 of the forming edge when the forming rolls 50 are drawn under and along such formed flange. The resistance of the edge 15 against such deflection is however, quite strong; hence, the formed fiange on the workpiece edge m will be pressed and in effect ironed out flat. This removes irregularities, and also tends to eliminate any springback. The resultant 180 flanges are so regular and smooth than conventional flattened C-shaped sheet metal drive cleats may be readily applied over them.

Variations in detailed design, to apply the present invention to modified uses, will be apparent to those skilled in the art. Accordingly, this invention is not to be construed narrowly, but rather as coextensive with the claims.

What is claimed is:

1. A rectilinear edge flanging tool for sheet metal workpieces and the like, comprising:

workpiece support structure having a rectilinear forming edge,

workpiece securing means adjacent thereto,

the support structure including a surface defining a workpiece support plane in which said forming edge lies,

the rectilinear forming edge having upper and under surfaces, and projecting blade-like with its upper surface in said support plane and its under surface therebeneath,

track means parallel therewith,

carriage means mounted on said track means,

means to draw the carriage along the track means, and

forming roll means carried by said carriage means along said forming edge and in workpiece forming adjacency thereto,

the workpiece securing means including a bar pivot-mounted outwardly of the forming edge and parallel thereto and above the level of the track and carriage means,

a plurality of spaced-apart clamp pads, each having an arm secured to the bar by which said clamp pad is positioned in a clamping position overlaying the support structure along and inwardly of the forming edge,

means to turn the bar in its pivot mount, whereby to lower the clamp pads to said clamping position and to raise them therefrom, and

means to secure the bar at the clamping position of said clamp pads.

2. A rectilinear edge flanging tool for sheet metal workpieces and the like, comprising:

workpiece support structure having a rectilinear forming edge,

workpiece securing means adjacent thereto,

the support structure including a surface defining a workpiece support plane in which said forming edge lies,

the rectilinear forming edge having upper and under surfaces, and projecting blade-like with its upper surface in said support plane and its under surface therebeneath,

track means parallel therewith,

carriage means mounted on said track means,

means to draw the carriage along the track means, and

forming rol1 means carried by said carriage means along said forming edge and in workpiece forming adjacency thereto, wherein the forming roll means includes a roll having a forming surface of revolution inclined downwardly and outwardly from the forming edge and extending pafitly above and partly below said support plane, an said carriage means further carries means, adjacent to the said forming roll and projecting beneath theunder surface of the blade-like forming edge, to support same against downward deflection. 3. A rectilinear edge flanging tool for sheet metal workpieces and the like, comprising:

workpiece support structure having a rectilinear forming edge, workpiece securing means adjacent thereto, the support structure including a surface defining a :YOIkplGCC support plane in Which said forming edge ies, the rectilinear forming edge having upper and under surfaces, and projecting blade-like with its upper surface in said support plane and its under surface therebeneath, track means parallel therewith, carriage means mounted on said track means, means to draw the carriage along the track means, and forming roll means carried by said carriage means along said forming edge and in workpiece forming adjacency thereto, wherein the forming roll means includes a roll having a forming surface of revolution inclined downwardly and outwardly from the forming edge and extending partly above and partly below said support, and said carriage means further carries an edge support roll on an axis which, when the carriage means is drawn along the track means, defines a plane parallel to and spacedly beneath the under surface of the forming edge, whereby to support the blade-like projecting forming edge against deflection caused by the downward inclination of the surface of revolution of the forming roll. 4. A rectilinear edge flanging tool for sheet metal workpieces and the like, comprising:

workpiece support structure having a rectilinear forming edge, workpiece securing means adjacent thereto, the support structure including a surface defining a workpiece support plane in which said forming edge lies, the rectilinear forming edge having upper and under surfaces, and projecting blade-like with its upper surface in said support plane and its under surface therebeneath, track means parallel therewith, carriage means mounted on said track means, means to draw the carriage along the track means, and forming roll means carried by said carriage means along said forming edge and in workpiece forming adjacency thereto, wherein the forming roll means comprises progressive forming rolls, each supported on an axis which, as the carriage is drawn along the track means, defines a plane substantially perpendicular to the plane of the work support surface, one of said progressive forming rolls including a forming surface of revolution inclined downwardly and outwardly from the forming edge and projecting partly above and partly below said support plane, whereby to bend a workpiece flange downward, and a subsequent forming roll including a forming surface of revolution directed inwardly beneath the undersurface of the projecting forming edge, whereby to form the workpiece flange upwardly against the under surface of said forming edge, there being on said carriage, adjacent to said first-mentioned forming roll, an edge support roll projecting beneath the forming edge on an axis which, when drawn by the carriage, defines a plane substantially parallel to and spacedly beneath the under surface of the forming edge,

the means to draw the carriage along the track means including means to effect a return stroke of said carriage along said track means,

whereby the said edge support roll will press the upwardly formed flange tightly against the work forming edge,

the projecting forming edge being characterized by spring-like resilience, whereby to deflect upward on such return stroke and thus accommodate the thickness of such flange between its under surface and the said support roll.

5. An edge flanging tool as defined in claim 4, together with means mounted on and traversable with said carriage and projecting beneath the under surface of the forming edge to bear against and press a flange, so formed, against said under surface.

6. A rectilinear edge flanging tool for sheet metal workpieces and the like, comprising:

workpiece support structure having a rectilinear forming edge, workpiece securing means adjacent thereto, the support structure including a surface defining a workpiece support plane in which said forming edge lies, the rectilinear forming edge having upper and under surfaces, and projecting blade-like with its upper surface in said support plane and its under surface therebeneath,

track means parallel therewith,

carriage means mounted on said track means,

means to draw the carriage along the track means, and

forming roll means carried by said carriage means along said forming edge and in workpiece forming adjacency thereto, wherein said forming roll means comprises a plurality of progressive forming rolls, and

a forming roll subsequent to the first includes a forming surface of revolution directed inwardly beneath the level of the under surface of the forming edge,

whereby, after a flange has been bent downwardly along the edge of a workpiece, to form same upwardly against said under surface.

7. An edge flanging tool as defined in claim 6, wherein said means to bear against and press the formed flange comprises a roller mounted on an axis which, on movement of the carriage along the track, defines a plane parallel to and below said blade-like projecting edge.

References Cited UNITED STATES PATENTS 78,486 6/ 1868 Serviss 72-220 243,352 6/1881 Beaman 72-220 709,754 9/ 1902 Ditchfield 72220 713,894 11/1902 MacFarren 72-220 2,982,331 5/1961 Bonner 72 -210 FOREIGN PATENTS 77,25 3 9/ 1894 Germany.

30 MILTON S. MEHR, Primary Examiner 

